Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data	Sep. 30, 2011	Mar. 31, 2011
Assets
Allowances for accounts receivable	$ 485	$ 436
Shareholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	30,000,000	30,000,000
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, no par value
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	30,403,067	30,312,758
Common stock, shares outstanding	23,010,653	22,893,803
Treasury stock, shares	7,392,414	7,418,955